I'm seeing the same problem.
The position of the accessory symbols seems to be very dependent on the relationship of the instrument relative to the focus point.
It is very difficult to select the accessory.
Once the accessory is selected, dragging it to the correct position has no effect. It doesn't move.
Changing the height of the instrument makes the accessory move relative to the instrument. - it seems to be following it's 3D position.
After adding a focus point or moving a focus point the instrument will follow the focus point in 3D, but the accessory needs to be refreshed in order to "track".
Kevin - any hints on how to handle this?
mk